scholarly journals A Systematic Review of Acoustic Telemetry as a Tool to Gain Insights Into Marine Turtle Ecology and Aid Their Conservation

2021 ◽  
Vol 8 ◽  
Author(s):  
Emily E. Hardin ◽  
Mariana M. P. B. Fuentes
Keyword(s):  
Systematic Review ◽  
Spatial Data ◽  
Acoustic Telemetry ◽  
Low Cost ◽  
Research Priorities ◽  
Marine Species ◽  
Marine Turtle ◽  
Home Ranges ◽  
Turtle Species ◽  
Marine Turtles

While widely applied in fisheries science, acoustic telemetry remains an underutilized method in the field of marine turtle biotelemetry. However, with the ability to provide fine-scale spatial data (tens to hundreds of meters, depending on array setup and receiver range) at a low cost, acoustic telemetry presents an important tool for obtaining key information on marine turtle ecology. We present a comprehensive and systematic review acknowledging how acoustic telemetry has been used to advance the field of marine turtle ecology and conservation. We identify the extent of current studies and discuss common and novel research approaches while addressing specific limitations of acoustic telemetry. Forty-eight studies were reviewed, representing six of the seven marine turtle species and all life stages, with most individuals identified as juveniles (45%) and hatchlings (36%). Most studies (83%) focused on the spatial distribution of marine turtles, including estimating home ranges, investigating drivers of habitat use, and identifying horizontal movement patterns and vertical space use. Additionally, acoustic telemetry has been used to study hatchling dispersal and marine turtle exposure and response to threats, as well as to monitor physiological parameters. We identified that acoustic telemetry directly or indirectly informs 60% of the top questions and research priorities related to marine turtles identified by experts in the field. With an increase in acoustic telemetry receiver networks and collaborations across taxa, the applicability of acoustic telemetry is growing, not only for marine turtles but for a wide array of marine species. Although there are limitations that need to be considered at a site/project-level, acoustic telemetry is an important, low-cost technology able to address key questions related to marine turtle ecology that can aid in their conservation, and therefore should be considered by researchers as they develop their projects.

scholarly journals Plastic ingestion by freshwater turtles: a review and call to action

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Adam G. Clause ◽  
Aaron J. Celestian ◽  
Gregory B. Pauly
Keyword(s):  
Marine Species ◽  
Marine Turtle ◽  
Freshwater Turtle ◽  
Freshwater Turtles ◽  
Plastic Pollution ◽  
Potential Threat ◽  
Implementation Quality ◽  
Turtle Species ◽  
Marine Turtles ◽  
Conservation Concern

AbstractPlastic pollution, and especially plastic ingestion by animals, is a serious global issue. This problem is well documented in marine systems, but it is relatively understudied in freshwater systems. For turtles, it is unknown how plastic ingestion compares between marine and non-marine species. We review the relevant turtle dietary literature, and find that plastic ingestion is reported for all 7 marine turtle species, but only 5 of 352 non-marine turtle species. In the last 10 years, despite marine turtles representing just 2% of all turtle species, almost 50% of relevant turtle dietary studies involved only marine turtles. These results suggest that the potential threat of plastic ingestion is poorly studied in non-marine turtles. We also examine plastic ingestion frequency in a freshwater turtle population, finding that 7.7% of 65 turtles had ingested plastic. However, plastic-resembling organic material would have inflated our frequency results up to 40% higher were it not for verification using Raman spectroscopy. Additionally, we showcase how non-native turtles can be used as a proxy for understanding the potential for plastic ingestion by co-occurring native turtles of conservation concern. We conclude with recommendations for how scientists studying non-marine turtles can improve the implementation, quality, and discoverability of plastic ingestion research.

scholarly journals Critical In-Water Habitats for Post-Nesting Sea Turtles from the Southern Gulf of Mexico

2021 ◽  
Vol 9 (8) ◽  
pp. 793
Author(s):  
Abigail Uribe-Martínez ◽  
María de los Angeles Liceaga-Correa ◽  
Eduardo Cuevas
Keyword(s):  
Gulf Of Mexico ◽  
Marine Ecosystem ◽  
Satellite Telemetry ◽  
Marine Turtle ◽  
Home Ranges ◽  
The Bahamas ◽  
Turtle Species ◽  
Southern Gulf Of Mexico ◽  
Large Marine Ecosystem ◽  
Physical Features

Marine turtles are globally endangered species that spend more than 95% of their life cycle in in-water habitats. Nevertheless, most of the conservation, recovery and research efforts have targeted the on-land habitats, due to their easier access, where adult females lay their eggs. Targeting the large knowledge gaps on the in-water critical habitats of turtles, particularly in the Large Marine Ecosystem Gulf of Mexico, is crucial for their conservation and recovery in the long term. We used satellite telemetry to track 85 nesting females from their beaches after they nested to identify their feeding and residency habitats, their migratory corridors and to describe the context for those areas. We delimited major migratory corridors in the southern Gulf of Mexico and West Caribbean and described physical features of internesting and feeding home ranges located mainly around the Yucatan Peninsula and Veracruz, Mexico. We also contributed by describing general aggregation and movement patterns for the four marine turtle species in the Atlantic, expanding the knowledge of the studied species. Several tracked individuals emigrated from the Gulf of Mexico to as far as Nicaragua, Honduras, and the Bahamas. This information is critical for identifying gaps in marine protection and for deciphering the spatial connectivity in large ocean basins, and it provides an opportunity to assess potential impacts on marine turtle populations and their habitats.

scholarly journals Natal foraging philopatry in eastern Pacific hawksbill turtles

2017 ◽  
Vol 4 (8) ◽  
pp. 170153 ◽  
Author(s):  
Alexander R. Gaos ◽  
Rebecca L. Lewison ◽  
Michael P. Jensen ◽  
Michael J. Liles ◽  
Ana Henriquez ◽  
...  
Keyword(s):  
Genetic Research ◽  
Eastern Pacific ◽  
Marine Turtle ◽  
Natal Philopatry ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Marine Turtles ◽  
Complex Processes ◽  
Natal Homing ◽  
Hawksbill Turtles

The complex processes involved with animal migration have long been a subject of biological interest, and broad-scale movement patterns of many marine turtle populations still remain unresolved. While it is widely accepted that once marine turtles reach sexual maturity they home to natal areas for nesting or reproduction, the role of philopatry to natal areas during other life stages has received less scrutiny, despite widespread evidence across the taxa. Here we report on genetic research that indicates that juvenile hawksbill turtles ( Eretmochelys imbricata ) in the eastern Pacific Ocean use foraging grounds in the region of their natal beaches, a pattern we term natal foraging philopatry. Our findings confirm that traditional views of natal homing solely for reproduction are incomplete and that many marine turtle species exhibit philopatry to natal areas to forage. Our results have important implications for life-history research and conservation of marine turtles and may extend to other wide-ranging marine vertebrates that demonstrate natal philopatry.

scholarly journals Assessing coastal artificial light and potential exposure of wildlife at a national scale: the case of marine turtles in Brazil

2020 ◽  
Vol 29 (4) ◽  
pp. 1135-1152 ◽  
Author(s):  
Liliana P. Colman ◽  
Paulo H. Lara ◽  
Jonathan Bennie ◽  
Annette C. Broderick ◽  
Juliana R. de Freitas ◽  
...  
Keyword(s):  
Nest Site Selection ◽  
Marine Turtle ◽  
Conservation Strategies ◽  
Brazilian Coast ◽  
Light Pollution ◽  
Artificial Light ◽  
Turtle Species ◽  
Marine Turtles ◽  
Light Levels ◽  
Nesting Beaches

AbstractCoastal areas provide critical nesting habitat for marine turtles. Understanding how artificial light might impact populations is key to guide management strategies. Here we assess the extent to which nesting populations of four marine turtle species—leatherback (Dermochelys coriacea), olive ridley (Lepidochelys olivacea), hawksbill (Eretmochelys imbricata) and two subpopulations of loggerhead (Caretta caretta) turtles—are exposed to light pollution across 604 km of the Brazilian coast. We used yearly night-time satellite images from two 5-year periods (1992–1996 and 2008–2012) from the US Air Force Defense Meteorological Satellite Programme (DMSP) to determine the proportion of nesting areas that are exposed to detectable levels of artificial light and identify how this has changed over time. Over the monitored time-frame, 63.7% of the nesting beaches experienced an increase in night light levels. Based on nest densities, we identified 54 reproductive hotspots: 62.9% were located in areas potentially exposed to light pollution. Light levels appeared to have a significant effect on nest densities of hawksbills and the northern loggerhead turtle stock, however high nest densities were also seen in lit areas. The status of all species/subpopulations has improved across the time period despite increased light levels. These findings suggest that (1) nest site selection is likely primarily determined by variables other than light and (2) conservation strategies in Brazil appear to have been successful in contributing to reducing impacts on nesting beaches. There is, however, the possibility that light also affects hatchlings in coastal waters, and impacts on population recruitment may take longer to fully manifest in nesting numbers. Recommendations are made to further this work to provide deeper insights into the impacts of anthropogenic light on marine turtles.

scholarly journals An ideal combination for marine turtle conservation: exceptional nesting season, with low nest predation resulting from effective low-cost predator management

Oryx ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 229-235 ◽  
Author(s):  
Richard Engeman ◽  
R. Erik Martin ◽  
John Woolard ◽  
Margo Stahl ◽  
Charles Pelizza ◽  
...  
Keyword(s):  
Nest Predation ◽  
Low Cost ◽  
Loggerhead Turtle ◽  
Chelonia Mydas ◽  
Economic Benefits ◽  
Marine Turtle ◽  
Management Approach ◽  
Predator Control ◽  
Marine Turtles ◽  
Predator Management

AbstractWe examined impacts from effective predator management on nesting success of marine turtles in an exceptional nesting year at Hobe Sound National Wildlife Refuge, Florida, USA, a beach with a high density of nesting marine turtles that has a history of severe nest predation. Historically up to 95% of nests were predated, primarily by raccoons Procyon lotor and, more recently, armadillos Dasypus novemcinctus. Predator control was identified as the most important conservation tool for marine turtle reproduction. Predator management by refuge staff as ancillary duties typically only held predation levels to c. 50%. However, when experts in predator control were employed predation was substantially reduced. An extraordinary opportunity to evaluate the biological and economic benefits of this management approach occurred in 2008, a year with exceptionally heavy nesting. Loggerhead turtle Caretta caretta nesting resurged, green Chelonia mydas and leatherback Dermochelys coriacea turtles nested in record numbers, producing twice or more than their median number of nests, and the first Kemp’s ridley Lepidochelys kempii nest was observed. Overall predation was 14.7%, resulting in an estimated > 128,000 additional hatchlings emerging compared to estimates had no predator management been in place and historical predation rates occurred, and > 56,000 hatchlings more than expected had predator management been conducted as ancillary duties rather than by experts. The USD 12,000 investment for expert predator management equated to only USD 0.09 spent for each additional hatchling produced compared to the scenario of no predator control and only USD 0.21 compared to the scenario of predator control as ancillary duties.

scholarly journals The evolution of the flippers and the paleoecology of Panchelonioidea (Testudines, Cryptodira)

2015 ◽  
Author(s):  
Isadora Gerheim ◽  
Pedro S. R. Romano
Keyword(s):  
Sister Group ◽  
Marine Turtle ◽  
Benthic Habitat ◽  
Remarkable Feature ◽  
Fossil Species ◽  
Turtle Species ◽  
Marine Turtles ◽  
The Family ◽  
Family Level ◽  
Pelagic Habitat

Background. The recent data on Panchelonioidea’s phylogeny suggested the family level relationships as (Toxochelyidae, (Cheloniidae, (Protostegidae, Dermochelyidae))). Despite the similarity between their limbs, it is known that the flippers morphology on marine turtles evolved independently in these clades. A remarkable feature is the presence of phalangeal condyles in Toxochelyidae and basal Protostegidae, a plesiomorphic state that allows the movement of the hand. On the other hand, the apomorphic state of having a rigid paddle is found in modern turtles (Cheloniidae and Dermochelyidae). Also, living Chelonioidea (Cheloniidae and Dermochelyidae) has the longest length of the hand and the shortest length of the humerus compared to other Testudines, as analyzed by Joyce and Gauthier (2004, Proc. R. Soc. Lond. B, 271). Methods. We took measurements of the forelimb (the length of humerus, ulna and digit III) from five Panchelonioidea fossil species (Protostega gigas, Toxochelys latiremys, Allopleuron hoffmanni, Eochelone brabantica and Archelon ischyros) using ImageJ 1.48v. The percentages of the length of the hand and the humerus with respect to the whole limb were then calculated. The percentages of the five species were added to the two-dimension ternary diagram made by Joyce and Gauthier (2004) in order to evaluate the plot of these species and compare them to other turtles. Results. Archelon ischyros was plotted near Toxochelys latiremys. The Toxochelidae are the sister group of Chelonioidea and they are known to have a poor development of the limbs into flippers and a preference for shallow and benthic habitat. Both were located near non-marine turtle species, showing that they had the relatively shortest hand within Panchelonioidea, whereas Protostega gigas, Allopleuron hoffmanni and Eochelone brabantica was plotted close to the recent Cheloniidae. Discussion. The results suggest a less pelagic habitat for Protostega gigas and Archelon ischyros, resembling a hypothesis formulated by Hay (1905, Bull. Am. Mus. Nat. Hist., 21) that Archelon was not as pelagic as Dermochelys and by Wieland (1909, Am. Jour. Sci., 27) that this species did not have a powerful type of muscular insertion, maybe indicating a less strong swimming power. These results together with the fact that basal species of Protostegidae retain the phalangeal condyles, suggests that after the split between these families, the flippers retained the primitive length of limbs. It also brings back a Zangerl’s hypothesis (1980, Amer. Zool., 20) of a Chelydra-like ancestor for Panchelonioidea, with unspecialized limbs. As conclusion, we suggest that Panchelonioidea ancestor flipper condition would last in stem Toxochelyidae and stem Chelonioidea and then get independently specialized in Cheloniidae and Dermochelyidae.

scholarly journals The evolution of the flippers and the paleoecology of Panchelonioidea (Testudines, Cryptodira)

2015 ◽  
Author(s):  
Isadora Gerheim ◽  
Pedro S. R. Romano
Keyword(s):  
Sister Group ◽  
Marine Turtle ◽  
Benthic Habitat ◽  
Remarkable Feature ◽  
Fossil Species ◽  
Turtle Species ◽  
Marine Turtles ◽  
The Family ◽  
Family Level ◽  
Pelagic Habitat

Background. The recent data on Panchelonioidea’s phylogeny suggested the family level relationships as (Toxochelyidae, (Cheloniidae, (Protostegidae, Dermochelyidae))). Despite the similarity between their limbs, it is known that the flippers morphology on marine turtles evolved independently in these clades. A remarkable feature is the presence of phalangeal condyles in Toxochelyidae and basal Protostegidae, a plesiomorphic state that allows the movement of the hand. On the other hand, the apomorphic state of having a rigid paddle is found in modern turtles (Cheloniidae and Dermochelyidae). Also, living Chelonioidea (Cheloniidae and Dermochelyidae) has the longest length of the hand and the shortest length of the humerus compared to other Testudines, as analyzed by Joyce and Gauthier (2004, Proc. R. Soc. Lond. B, 271). Methods. We took measurements of the forelimb (the length of humerus, ulna and digit III) from five Panchelonioidea fossil species (Protostega gigas, Toxochelys latiremys, Allopleuron hoffmanni, Eochelone brabantica and Archelon ischyros) using ImageJ 1.48v. The percentages of the length of the hand and the humerus with respect to the whole limb were then calculated. The percentages of the five species were added to the two-dimension ternary diagram made by Joyce and Gauthier (2004) in order to evaluate the plot of these species and compare them to other turtles. Results. Archelon ischyros was plotted near Toxochelys latiremys. The Toxochelidae are the sister group of Chelonioidea and they are known to have a poor development of the limbs into flippers and a preference for shallow and benthic habitat. Both were located near non-marine turtle species, showing that they had the relatively shortest hand within Panchelonioidea, whereas Protostega gigas, Allopleuron hoffmanni and Eochelone brabantica was plotted close to the recent Cheloniidae. Discussion. The results suggest a less pelagic habitat for Protostega gigas and Archelon ischyros, resembling a hypothesis formulated by Hay (1905, Bull. Am. Mus. Nat. Hist., 21) that Archelon was not as pelagic as Dermochelys and by Wieland (1909, Am. Jour. Sci., 27) that this species did not have a powerful type of muscular insertion, maybe indicating a less strong swimming power. These results together with the fact that basal species of Protostegidae retain the phalangeal condyles, suggests that after the split between these families, the flippers retained the primitive length of limbs. It also brings back a Zangerl’s hypothesis (1980, Amer. Zool., 20) of a Chelydra-like ancestor for Panchelonioidea, with unspecialized limbs. As conclusion, we suggest that Panchelonioidea ancestor flipper condition would last in stem Toxochelyidae and stem Chelonioidea and then get independently specialized in Cheloniidae and Dermochelyidae.

scholarly journals Genomic Variation of the Fibropapilloma-Associated Marine Turtle Herpesvirus across Seven Geographic Areas and Three Host Species

2005 ◽  
Vol 79 (2) ◽  
pp. 1125-1132 ◽  
Author(s):  
Rebecca J. Greenblatt ◽  
Sandra L. Quackenbush ◽  
Rufina N. Casey ◽  
Joel Rovnak ◽  
George H. Balazs ◽  
...  
Keyword(s):  
Chelonia Mydas ◽  
Genomic Variation ◽  
Open Reading Frames ◽  
Marine Turtle ◽  
Neoplastic Disease ◽  
Geographic Variations ◽  
Turtle Species ◽  
Marine Turtles ◽  
Simplex Virus ◽  
Reading Frames

ABSTRACT Fibropapillomatosis (FP) of marine turtles is an emerging neoplastic disease associated with infection by a novel turtle herpesvirus, fibropapilloma-associated turtle herpesvirus (FPTHV). This report presents 23 kb of the genome of an FPTHV infecting a Hawaiian green turtle (Chelonia mydas). By sequence homology, the open reading frames in this contig correspond to herpes simplex virus genes UL23 through UL36. The order, orientation, and homology of these putative genes indicate that FPTHV is a member of the Alphaherpesvirinae. The UL27-, UL30-, and UL34-homologous open reading frames from FPTHVs infecting nine FP-affected marine turtles from seven geographic areas and three turtle species (C. mydas, Caretta caretta, and Lepidochelys olivacea) were compared. A high degree of nucleotide sequence conservation was found among these virus variants. However, geographic variations were also found: the FPTHVs examined here form four groups, corresponding to the Atlantic Ocean, West pacific, mid-Pacific, and east Pacific. Our results indicate that FPTHV was established in marine turtle populations prior to the emergence of FP as it is currently known.

scholarly journals The marine turtles of Belize

Oryx ◽  
1985 ◽  
Vol 19 (3) ◽  
pp. 155-157
Author(s):  
Don Moll
Keyword(s):  
Legal Protection ◽  
Marine Turtle ◽  
Turtle Species ◽  
Marine Turtles ◽  
Closed Season

When the author visited Belize in 1983 and 1984 to survey the turtle fauna of that country, to which the Oryx 100% Fund contributed £500, he was able to collect some information on the three marine turtle species that nest on Belize's beaches and forage along the coast. All three species are exploited in the country and, although there is a degree of legal protection, the ban on egg-collecting is widely ignored, turtles are taken for their meat in the closed season, and tortoise-shell jewellery and curios still find a ready market among tourists from abroad.

scholarly journals Ecological Vulnerability of Adult Female Marine Turtles as Indicators of Opportunities for Regional Socioecosystem Management in the Southern Gulf of Mexico

2021 ◽  
Vol 14 (1) ◽  
pp. 184
Author(s):  
María de los Angeles Liceaga-Correa ◽  
Abigail Uribe-Martínez ◽  
Eduardo Cuevas
Keyword(s):  
Endangered Species ◽  
Gulf Of Mexico ◽  
Protected Areas ◽  
Marine Turtle ◽  
Natural Protected Areas ◽  
Turtle Species ◽  
Marine Turtles ◽  
Ecological Vulnerability ◽  
Southern Gulf Of Mexico ◽  
Functional Components

Planning for marine ecosystems management demands spatially explicit information about structural and functional components, in a tradeoff between including the most taxa and keeping it functional. Sentinel, umbrella, and surrogate taxa are strategic for developing indexes that account for other associated species and contribute to a sustainable administration of our seas. Marine turtles feature the former species descriptions, and the knowledge on their ecology contributes to design conservation and restoration strategies in regions they occupy, such as the Gulf of Mexico. Several administrative tools exist to govern marine territories for biodiversity conservation, and assessing how these tools interact with the ecological vulnerability of endangered species is crucial for improving public policies. We assessed the spatial interactions among ecological sensitivity, vulnerability, and the potential impacts on four marine turtle species in the southern Gulf of Mexico and northwestern Caribbean Sea with territorial management tools (natural protected areas, marine priority sites, and ecoregions). A small percentage of the most vulnerable areas is inside natural protected areas, while marine priority sites include a higher percentage. We identified spatial covering gaps that need to be addressed to ensure the conservation and recovery of these endangered species in the Gulf of Mexico and proposed key regions for maximizing territorial conservation.

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